In a mobile telephone network, load balancing is required to share scarcely available radio resources and the processing load between available base stations (referred to as eNBs in E-UTRAN). In order that this load balancing can take place, load measurements are made by the base stations and shared with the neighbouring base stations, so that decisions on load balancing can be taken. In the RAN1#51B is meeting in Seville 14 to 18 Jan. 2008, the load balancing mechanism was discussed. In particular, RAN1 discussed the physical layer measurements needed to support efficient load balancing and agreed that the measurements of the physical resource block usage in the uplink and the downlink are relevant for load balancing. They have proposed the following four different measurements for this purpose:
1) Physical resource block usage for GBR (real time traffic) on UL
2) Physical resource block usage for non-real traffic on UL
3) Physical resource block usage for GBR (real time) traffic on DL
4) Physical resource block usage for non-real time traffic on DL
All these measurements are defined as a ratio (percentage) of the used Physical Resource Blocks (PRBs) for a type of traffic over the available PRBs in the same direction over a certain time interval, and are measured per cell. Any non-scheduled transmissions and retransmissions should also be counted as used.
Further, RAN 1 believes that it would be sufficient if this control is done at a periodicity in the order of seconds to minutes, or even at a slower rate depending on the expected traffic fluctuation such as for busy hours.
However, details of the signalling of this information between the base stations for load balancing have yet to be defined.
Although for efficiency of understanding for those of skill in the art the invention will be described in detail in the context of a 3G system, the principles of the handover procedure can be applied to other systems, e.g. other CDMA or wireless systems in which mobile devices or User Equipment (UE) communicate with one of several other devices (corresponding to eNB) with the corresponding elements of the system changed as required.